SIBLEY COUNTY, Minnesota (KARE) – A Sibley County, Minnesota farmer has confirmed his two year-old rare discovery.

It’s a rare meteorite dating back some 4 billion years.

Bruce and Nelva Lilenthal recently took the 33 pound object to the curator of meteorites at the University of Minnesota in St. Paul.

Crops aren’t the only thing Lillenthal harvests: He also saves unique rocks he finds in his fields and piles them near the driveway of his farm near Arlington. Curiosity about one particular rock he found two years ago finally got the best of Lilenthal’s wife, Nelva.

The couple finally decided to take the rock to professor Calvin Alexander, who says the Lillenthal’s meteorite is rare and likely four billions of years old.

Alexander says he’s looked at an estimated 5,000 rocks over the years that were thought to be meteorites, but instead turned out to be “meteor-wrongs,” as the professor affectionately refers to them.